Burglar-alarm



AND J. B. DAWSON. LAR ALAR FILED DEC- I919.

Patented Feb. 8, 1921.

W; W. GERRIE BURG APPLICATION UNITED STATES PATENT OFFIQE.

WALTER W. GERRIE AND JAMES B. DAVISON, O1 OAKLAND, CALIFORNIA; SAID GERRIE ASSIGNOR OF HIS ENTERE RIGHT TO LEONARD NEXVPORT, OF OAK- LAND, CALIFORNIA. s

Specification of Letters Patent.

BURGLAR-ALARM.

Patented Feb. 8, 1921.

Application filed December is, 1919. Serial No. 345,371.

7 '0 all whom it may concern Be it known that we, WALTER W. Gnnmr. and detains B. DAWSON, citizens of the United States, residing in Gakland, in the county of Alameda and State or" California, have invented a certain new and useful Improvement in Burglar-Alarms, of which the following is a specification.

Our invention relates to improvements in burglar alarms wherein a plurality of explosive caps operate in conjunction with an impacting shoe, to explode said caps when a window is opened by unauthorized persons.

The primary object of our invention is to provide an improved burglar alarm.

It is also an object to provide improved and simplified means for sounding an alarm when unauthorized entrance to a compartment is sought through a window or the like.

Another object is to provide improved means whereby either or both sashes of a window may be set partly opened for ventilating purposes and secured against further opening without sounding an alarm.

Another object. of the invention is to provide means for decreasing the morale and alarming intruders seeking an unauthorized entrance into a compartment or the like.

\Ve accomplish these several objects by means of the improved device disclosed in the drawings forming a part of the present specification wherein like characters of reference are used to designate similar parts throughout the said specification and drawings, and in which:

Figure 1 is a broken sectional view of adjoining sashes oi a window disclosing our improved alarm attached thereto.

Fig. 2 is a broken side elevation of Fig. 1.

Fig. 8 is a broken sectional view of two sashes partly opened with the device in position, and

Fig. 1 is a sectional View taken on line H of Fig. 2 in the direction indicated.

Referring to the drawings the numeral 1 is used to designate a window having upper and lower sashes 2 and 3 respectively. Upon one side oi the upper sash 2 is a vertically disposed strip -it provided with a series of alined apertures 6 within which are detachably inserted explosive caps 7 These caps 7 are arranged to be exploded by impact the purpose of which will hereinafter be more fully described.

The strip 1 may be detachably secured to the sash 2 by means'oi any suitable mechanism, not shown, whereby said strip may be temporarily removed to "facilitate the renewal of the caps 7.

Mounted upon the lower sash is a suitable window lock designated in general by the numeral 8 and having a shoe 9 provided with a recess 11 adapted to inclose and explode the nearest explosive cap 7 by means of one of the inner ends or" the recess 11 when either sash is moved relatively to the other.

Normally the shoe 9 is mounted to engag and explode by impact one or more of the caps 7 when the top sash is lowered or the lower sash is raised but the said shoe 9 may be receded to prevent contact thereof with the caps 7 by means of the lever 12 which is provided with a cam 14 operating within a recess 16 of the said shoe 9.

The recess 11 0t theshoe 9 is provided to l11( lose the cap 7 and prevent the same from being discharged away from the Window 1 and possibly injuring an operator engaged in raising or lowering one of the sashes.

The sashes 2 and 3 may be partly opened and the shoe 9 closed against the upper sash as disclosed in Fig. 3 of the drawings, in which case any attempt to further open either sashwill produce a contact of the shoe 9 with the nearest cap 7 and thereby sound analarm.

\Vhen a cap is exploded by the action of an intruder in opening either sash the resulting report is bound to decrease or lower the morale of the intruder and frighten him away as the explosion may convey to.

him the impression that an observer has fired a firearm either at him or to attract the attention oi the proper authorities to his presence.

The details of construction are so susceptible to variation that we do not wish to confine ourselves to the precise details of construction disclosed herein, as it is obvious that any form of securing means for the caps or any form of recedable shoe coacting therewith will tend to produce the desired result. Therefore, we wish to avail ourselves of any modification that may fall properly within the scope of our invention.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is: v

1. A burglar alarm comprising a perforated strip adapted for detachable engagement with one side of one sash of a window; explosive elements detaehably mounted with in the perforations of the strip and adapted to be exploded by impact; a recessed element adapted to be mounted upon the other sash of the window and arranged to cause the re-' cess therein to inc-lose and explode one or more of said explosive elements by impact of one of the inner surfaces of said recess with said explosive elements when either window is moved; and means for retarding the recessed elements to prevent contact with said explosive element when either window is'moved. 3 a

2. A burglar alarm comprising an apertured strip adapted for detachable engagement with one side of one sash of a window; a plurality of explosive caps detachably mounted within the apertures of the strip and adapted to be exploded by impact; and a. recessed shoe movably mounted upon the when either sash is moved.

3. A burglar alarm comprising an apertured strip adapted for detachable engagement with one side of one sash of a window; a plurality of explosive caps detach-ably mounted within the apertures of the strip and adapted to be exploded by impact; and a reressed shoe movably mounted upon the other sash of the window and arranged to cause the recess therein to inclose and explode 'one or more of said explosive caps when either sash is moved; and means for receding the recessed shoe to'prevent contact thereofwith the explosive caps when either sash is moved.

In witness whereof we hereunto set our signatures. I

WALTER W. GERRIE. JAMES B. DAWSON. 

